.\" $OpenBSD: SMIME_crlf_copy.3,v 1.3 2023/05/01 07:28:11 tb Exp $
.\"
.\" Copyright (c) 2021 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: May 1 2023 $
.Dt SMIME_CRLF_COPY 3
.Os
.Sh NAME
.Nm SMIME_crlf_copy
.Nd buffered copy between BIOs
.Sh SYNOPSIS
.Ft int
.Fo SMIME_crlf_copy
.Fa "BIO *in_bio"
.Fa "BIO *out_bio"
.Fa "int flags"
.Fc
.Sh DESCRIPTION
.Fn SMIME_crlf_copy
copies data from
.Fa in_bio
to
.Fa out_bio .
To avoid many small write operations on
.Fa out_bio ,
a buffering BIO created with
.Xr BIO_f_buffer 3
is temporarily prepended to it.
.Pp
If the bit
.Dv SMIME_BINARY
is set in the
.Fa flags
argument, all the data is copied verbatim using
.Xr BIO_read 3
and
.Xr BIO_write 3 .
.Pp
Otherwise, the data is read as text.
All trailing carriage return and newline characters are discarded
from every input line and a single pair of carriage return and
newline characters is appended to mark the end of every output line,
except that the last output line will end without such a pair if
the last input line does not have a newline character at the end.
.Pp
If the bit
.Dv SMIME_TEXT
is set in the
.Fa flags
argument and the bit
.Dv SMIME_BINARY
is not set, the line
.Qq Content-Type: text/plain
is prepended to the output
with two pairs of carriage return and newline characters after it.
.Pp
In any case,
.Xr BIO_flush 3
is called on the output at the end of the function.
.Sh RETURN VALUES
.Fn SMIME_crlf_copy
is intended to return 1 on success or 0 on failure.
.Sh SEE ALSO
.Xr BIO_f_buffer 3 ,
.Xr BIO_flush 3 ,
.Xr BIO_new 3 ,
.Xr BIO_push 3 ,
.Xr BIO_read 3 ,
.Xr SMIME_text 3 ,
.Xr SMIME_write_ASN1 3
.Sh HISTORY
.Fn SMIME_crlf_copy
first appeared in OpenSSL 1.0.0 and has been available since
.Ox 4.9 .
.Sh BUGS
.Fn SMIME_crlf_copy
silently ignores most errors and may return 1
even if it lost part or all of the data in transit.
.Pp
Only blocking BIOs are supported.
If any of the
.Vt BIO
arguments is non-blocking, part or all of the data is likely
to be silently lost in transit.
